Process and apparatus for forming and annealing sheet glass



M r 1932- J. c. BLAIR PROCESS AND APPARATUS FOR FORMING AND ANNEALINGSHEET GLASS Filed Sept. 18. 1929 MIN AN an Q JAMES o. BLAIR, orroiiEna'oHIO;.Assrenon 'ro'mnnnv-owms-ronn oLAs's-oom I Patented Mar. 8,v1932 PANY, or TOLEDO, OHIO, A 'ooaronarroiv on 01nd e frnoonssarrnnn'rus masonmaam mnmtm sm emss Application filed September 13, 1929Serial i The present invention relates to animproved process andpparatusfor forming and: annealing sheetor plate glass.

In the manufacture of sheet-"glass accord ing to ione'process.a'plurality of successlve sheets of glass are intermittentlyrolled atpredetermined intervals from a series of charges of molten glass Themolten glass is preferably melted and refined 'withinsuitablereceptacles or pots and discharged there from onto a receiver froniwherethe lass is moved to and passed between a pairo "forming'rolls andreduced thereby to a sheet of substantially predetermined and uniformthickness. In carrying out the process just described, it isdesirable,"in orderto increase production and improve the 'qualityfofthe glass sheets, that they be formed at a rela' j tively high rate ofspeed or, in other words,-

that the molten glas's'passin'g to the forming rolls be 7 rapidlyreduced-to "sheet" form.

While it is desirable to'reduce'the rapidly to's'heet formyit'isnotnecessarythatthe sheet be-annealed'while traveling at this same highrateof speed. In fact, such is un'desir-Q able for the reasonthat inthis event the an- I nealing leer necessary would haveto be ex ceedinglylong. For example, if the glass Y were' rolled to sheet format the rateof siXty feet per minuteand'should' it take sixty min; utes' to annealthe glass,it will be seen that the length of leer necessary would havetobe 3600feet. The disadvantages incidenttothe' construction, operationand maintenance of a leer of 'thislengt'h are believed to'be'obvi U p v7 c :th'r'ough the forwardendportion of appa,-- ra tus constructed .in"accordance with a the ousi x v The object of the inventi'on broadlystated; is in the provision of a process and apparatus wherein glasssheets may be formed at a relinvention aims to providea process and apparatus which'will embody those advantages incident to the rapidreduction'ofthe molten glass to sheet formgand likewise'those, ad-

I "vantages whichresult from-slower annealing of the glass. 7

" 'iAnother object of the inventionfisthg 6; Vision of u 'P Q andapparatus when;

taken in? connection with the accompanyi V vdrawingsf' I a the same;

in thespeed of travel-'ofthe sheetssubsequent 1 v ing causedito travelat variable speeds during V x I its forward movement so asto facilitatethe desired cooling and annealing thereof.

- 'A' further'obje'ct of the invention is to pro vide's'uch aprocessandappara tus wherein the glass sheet is" formed at a relatively high 70rate of speed and carried forwardly into and through an annealing leer,vsaid sheet "being caused to travel intermittently throughfthe leer atan average speed'whioh is relatively i less than its speed of'formation.I

Other ob eots and-advantagesof the inven I tion will" become-moreapparent, during the course -of the following "description when I so "Inthe drawings "forming -'a "part of' this application and'wherein likenumeral s'are V employed to designate like parts throughout Fig. 1 is aertical?ibn audiaal se s-n 'horizontalposi tion "as indicated by thebrokenilines invFig, 1, after which said receiver is'tilted to its fullline positioniso that theIOOj conveying 'tahle;17 which :may be termedthe cooling section of the-apparatus. This cooling section is composedof a plurallty of henzontally arranged rolls IB-carried V byshaftsjournaled at their opposite ends in the side.

members19 and 20 whichare supportedat" their opposite ends uponstandards orsupports 21. The rolls 18 of cooling section 17 are adaptedto be driven in :unison and this may be accomplished through a chaindrive 22 associated with the :roll shafts and driven from a variablespeed motor or the like 23 or in any other desired manner,

Arrangedat the endof the cooling section 17 is a relatively longtunnel-like housing designated in its entirety by the numeral 24 anddivided into a transfer section 25 and an annealing section26, the twosections being divided'by a vertical partition wall 27 :having a slot 28therein through which the sheet passes from the transfer section intothe annealing section. The sheet is adapted .to be carried through thetransfer section. 25 upon a plurality of'hori-zontally arrangedrolls 29in horizontal alignment with the rolls 18 0f cooling section 17, saidrolls having associated therewith a chain drive 30 operatedby a variablespeedmotor 31. r g p n V p The annealinglsection 26 is providedwith aplurality of 'rolls32 in horizontal -alignment'with the rolls 18 and 29referred to above. The rolls 32 are likewise driven in unison from a"separate -motor 183 and chain drive34 or byany othersuitablemeans. Thetemperatureof the annealing section- 26 -may be controlled in anypreferred manner-such as by theprovision of a pluralityofiburners or thelike 35. From the above, it will be seenlthatthe rolls of thecooling-section 17 transfersection 25 and annealing section 26 aredriven independently of one another.

, As above pointed out, it is desirable that the glass sheet 15 beformed at a relatively high rate of speed and the forming rolls 13 and14 1 are consequently driven in a manner that their peripheral speedwill besuch that they will function torapidly reduce the mass of molten,glass to sheet form. One of- 'the forming rolls may be positively driyenby a suitabledriving means 86 and the 01211612 1 011 driven "from thepositively driven roll through intermeshing vgears "37 mounted upon theroll shafts 38.

p In carrying the inven'tion into practice, a mass of molten;.glass1:1.is first placed -upon the receiver .10 and thengmoved therefromtion, namely, sixty feet per minute so as "to rece ve :thelglass :sheet:asut 1s iformed'a'and carry the same forwardly. Thus, the sheet runsout on the cooling section 17 at rolllng speed until the tall {or rearend thereof has cleared or passed from the runway 16. The speed of themills '18 is then materially reduced to say approximately ten feet perminute and the sheet is carried valong at ,this speed for a desiredlength offltime to allow for the required cooling andvsetting thereof.This coolingispeed iscontinued untilthe head or forward'end of the sheetapproaches the transfer seetion 25 whereupon the lspeed of the rolls18is increased toaspeed relatively greater than the "speed "of sheetvformation, for example, to 12O-feet per minutehso-asito feed the sheetquickly-into 'the transfer i-section f25wher einit will be.su-pported'and carried along upon rolls 29. During the feeding ofthesheetzinto the transfer section 25, the: rolls 29 of said \sectionare synchronized with thehigh speed of the rolls 18 on-in if otherwords, are also driven at a speed of 120 feetper minute to receive thesheet-therefrom, 7 1

After the sheet hasbe'en entirely deposited upon the rolls 2910ftransfer sectionr25, its speed of travelhis again materially reduced'toa speedlless than the forming-speed but, preferably no't quite s low: asthe .coo1ing;speed say, approximately'fifteenffeet per minute.

The sheet is carried along vat-this speedinto the annealing: section 26during which-time thezrolls 32 thereof 1 are -drivenat the 1 same speedas the transfer T011329. After the sheet has been entirely receiyedwithin the annealing section 26,.therotation of .the rolls 32 isstoppedso as lto bring the sheet tea standstill and vthe sheet:maintained -stationary until the next sheet formedeapproaches the same,whereupon the rolls 532 are again synchronized with the transfer rolls29 to receive theneXt sheet from thetransfer section. lnthis manner,theshe'etsiare caused to travel intermittently through the leer, theglass sheet remaining stationaryzwithin the leer duringtheformationof-each succeeding sheet and travelingonlyduring the'transferof 1 each sheet from the transfer sectioninto theannealing section. From-the.above, it will be seeneth-at therolls-ofthe cooling 1 section .17areadapted to travel atiaspeed equal to the speed of, sheet formation,:at ca :relatively slower speed and also at a-relatilvely higher speed,the rolls of, the transfer section 225 being; driven at raspee d i equalto the high speed of the cooling section and also at V .a slower speed,While the rolls ofthe annealingsection 26 are adapted to travelinstopping the sheet upon itsentrance into porating the principle of the20 v the leer, the following sheet can close the gap between thesheetsto the desired minimum before the sheet is again caused to travel,

through the leer. ,The relative speeds herein given are by Way ofexample only and the invention is notto be construed as limited theretosince a wide range of speeds, incorpresent invention, may be utilized. a

It is to be understood that the form of the invention herewith shown anddescribed is to be'taken as the preferred embodiment of the same, andthat various changes in the shape, size and arrangement of parts may beresorted to Without departing from the spirit of the invention or thescope of the subjoined claims. 7

'I' claim:

1. The process of producing sheet glass,

reducing the speed of travel of the sheet to ef- 7 feet the desiredcooling and setting thereof,

increasing. the speed of travel of the sheetto a speed relativelygreater than its speed of formation and'delivering it'at such speed intoa protective enclosure, again reducing the speed of travel of the sheetafter it is Within such enclosure to a speed relatively lessthan theforming speed but not as low as the cooling speed and in deliveringthesheet at such speed into an annealing zone, and in annealing the'sheetvvhile traveling intermittently through said zone-at anaveragespeed relatively less than its speed of forination.

5. In apparatus for producing sheet glass, means for reducing a mass ofmolten glass to 'sheet'form, an annealing leer, and means for receivingthe sheet from the forming means and conveying it into and through saidleer,

including a variable speed cooling section, a variable speedtransfersection, and an lntermittently traveling annealing section.

6. In apparatus for producing sheet glass,

means for reducing a mass of molten glass to sheet form, an annealingleer, and means for receiving'the sheet from the forming means andconveying 'itinto and'through said leer,

including a, cooling section, means for driving said section at variablespeeds, a transfer section, separate means for driving said trans-

